How can I calculate force required to destroy of a iron hollow closed cylinder when we have internal exploding ? i want to calculate (Δx) and get the energy by Forced * (Δx) , so i should have strain Use ultimate tensile or stress of Pr/t for calculating strain of destroying of explosion ?

Are you trying to calculate the maximal internal pressure a cylinder can resist ? If you are, you have to take several stresses in account and you have to define the static failure criteria you want. Here is a summary of piping stresses, I've highlighted the equations you'll need : (direct link : http://i1189.photobucket.com/albums/z434/Virgule99/Piping/Piping_Stress_pressure.png) NB: - The pressure P is the relative pressure (difference between inside and outside pressure) - There are other failure modes (impact, fatigue,...) that can cause rupture at stresses under static failure stresses